1. Field of the Invention
The present invention relates to a photovoltaic system.
2. Description of the Related Art
In general, in a photovoltaic (PV) system, a PV module of a capacity larger than the rated capacity of a power conditioner (PCS, power conditioning system) is installed. When the electricity of the PV module exceeds the rated capacity of the PCS, the PCS limits its output below the rated capacity.
In order to control a PV system, called a mega solar power plant, which has a large capacity of several to several tens of megawatts, a main site controller (MSC) may be employed. The MSC performs power generation control of the mega-solar power plant, as well as centralized monitoring of a plurality of PCSs in the mega solar power plant.
For instance, the MSC performs the following power limit control: When the output of part of the PCSs decreases, for example, in the cloud cover, the MSC increases the output of other part of the PCSs that have a margin in output. Thus, the MSC performs control so that the power generated by the mega solar power plant will always be maximum at an active power limit (see Non-patent Document 1).
However, since each PCS limits electricity generated by a corresponding PV module not higher than the rated capacity, it cannot fully utilize the power generation capacity of the PV system, even if the MSC performs the above-mentioned power limit control.